diff --git a/common/hw-gfx-gma-config.ads.template b/common/hw-gfx-gma-config.ads.template
index 4f374fd..cba1396 100644
--- a/common/hw-gfx-gma-config.ads.template
+++ b/common/hw-gfx-gma-config.ads.template
@@ -203,4 +203,18 @@
          when Sandybridge  => Full_Training,
          when others       => Auto_Training);
 
+   ----------------------------------------------------------------------------
+
+   Default_RawClk_Freq : constant Frequency_Type :=
+     (case CPU is
+         when Ironlake     |
+              Sandybridge  |
+              Ivybridge    => 125_000_000,
+         when Haswell      |
+              Broadwell    => (if CPU_Var = Normal then
+                                 125_000_000
+                               else
+                                 24_000_000),
+         when Skylake      => 24_000_000);
+
 end HW.GFX.GMA.Config;
diff --git a/common/hw-gfx-gma-registers.ads b/common/hw-gfx-gma-registers.ads
index d42d4bb..1633bac 100644
--- a/common/hw-gfx-gma-registers.ads
+++ b/common/hw-gfx-gma-registers.ads
@@ -349,7 +349,7 @@
       PCH_FPB0,
       PCH_FPB1,
       PCH_DREF_CONTROL,
-      RAWCLK_FREQ,
+      PCH_RAWCLK_FREQ,
       PCH_DPLL_SEL,
       PCH_PP_STATUS,
       PCH_PP_CONTROL,
@@ -1014,7 +1014,7 @@
       TRANS_VSYNCSHIFT_A    => 16#0e_0028# / Register_Width,
       TRANS_VSYNCSHIFT_B    => 16#0e_1028# / Register_Width,
       TRANS_VSYNCSHIFT_C    => 16#0e_2028# / Register_Width,
-      RAWCLK_FREQ           => 16#0c_6204# / Register_Width,
+      PCH_RAWCLK_FREQ       => 16#0c_6204# / Register_Width,
       QUIRK_C2004           => 16#0c_2004# / Register_Width);
 
    subtype Registers_Index is Registers_Invalid_Index range
diff --git a/common/hw-gfx-gma.adb b/common/hw-gfx-gma.adb
index 9e3bee9..416117b 100644
--- a/common/hw-gfx-gma.adb
+++ b/common/hw-gfx-gma.adb
@@ -78,6 +78,16 @@
 
    ----------------------------------------------------------------------------
 
+   PCH_RAWCLK_FREQ_MASK                : constant := 16#3ff# * 2 ** 0;
+
+   function PCH_RAWCLK_FREQ (Freq : Frequency_Type) return Word32
+   is
+   begin
+      return Word32 (Freq / 1_000_000);
+   end PCH_RAWCLK_FREQ;
+
+   ----------------------------------------------------------------------------
+
    function To_GPU_Port
      (Configs  : Configs_Type;
       Idx      : Config_Index)
@@ -712,6 +722,11 @@
       -------------------- Now restart from a clean state ---------------------
       Power_And_Clocks.Initialize;
 
+      Registers.Unset_And_Set_Mask
+        (Register    => Registers.PCH_RAWCLK_FREQ,
+         Mask_Unset  => PCH_RAWCLK_FREQ_MASK,
+         Mask_Set    => PCH_RAWCLK_FREQ (Config.Default_RawClk_Freq));
+
       Initialized := True;
 
    end Initialize;
diff --git a/common/hw-gfx.ads b/common/hw-gfx.ads
index 8c1fcf7..b9d7225 100644
--- a/common/hw-gfx.ads
+++ b/common/hw-gfx.ads
@@ -42,7 +42,7 @@
        Stride => 1,
        Offset => 0);
 
-   subtype Frequency_Type is Pos64 range 25_000_000 .. 600_000_000;
+   subtype Frequency_Type is Pos64 range 24_000_000 .. 600_000_000;
 
    type DP_Lane_Count is (DP_Lane_Count_1, DP_Lane_Count_2, DP_Lane_Count_4);
    subtype DP_Lane_Count_Type is Pos64 range 1 .. 4;